1. Field of the Invention
The present invention relates to a method for detecting an endpoint of development, more particularly, to a method for reliably detecting an endpoint of development of a resist used in the production of semiconductor devices.
2. Description of the Related Art
In the production of semiconductor device, a resist is developed using the difference of solubilities of the exposed and unexposed portions. There has been no appropriate method for detecting the progress of the development. Accordingly, the development process has heretofore been dependent upon the skill of the operators. Skilled operators have been able to satisfactorily control the development process so long as the temperature of the developing solution and the developing time are strictly controlled.
The recent increase in the integration of semiconductor circuit elements, however, has resulted in finer interconnections on the substrate and narrower distances between adjacent lines. This necessitates a more complicated resist pattern and higher precision. Even skilled operators find it difficult to handle this and often overdevelop or underdevelop the resist.